Fasting Post-Refeed

What's the data on the effects of a 20-24 fast after a refeed? Does the fast negate the leptin boost that the refeed is designed to provide? Will your body draw on those now refilled glycogen stores directly afterward, or does it continue to use fat as its primary fuel (assuming fat adaptation)?

i question the whole leptin boost bit, but once the post-prandial insulin spike passes, you'll burn whatever fuel is appropriate for the activity you're doing (i.e. running, walking, sitting - is it glycolytic work?). liver glycogen will deplete in this case, in order to fuel your brain, but muscle glycogen won't... unless you do glycolytic work.